A couple of things; the sliders might not use the same kind of keys as the swing doors. The swing doors will be easy to change if they're standard, the sliders might take some investigation and head-scratching. At least with them a dowel in the track will secure them while you have the lock out for matching.
Depending on the age of the locks, replacement might be a better long-term investment. Older sets can be very worn or less attractive with wear and corrosion. One thing that can throw people is proper installation of a deadbolt strikeplate, it can involve mortising out the jamb deeper than in the old days.
Another thing to consider is making the door into the garage, if there is one, as lockable as the front door. If you go the deadbolt route, it's much safer in an emergency if the inside of the deadbolt is a thumblatch and not keyed like the outside.
